E

Visitor

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5 Messages

Tuesday, January 24th, 2023 6:17 PM

Frequent disconnects: No Response received, T3 time-out

Hi,

I've been getting a lot of connection drops lately, some taking quite a while to recover.

Modem+Router: Netgear C7000v2
Adapter: Netgear A7000

At first I thought it had to do with the A7000 or with congested channels. After doing troubleshooting on both of those, I read some posts on this forum about similar errors found in modem logs. I'm thinking it maybe has more to do with the cable lines themselves.

After reaching the house, the line runs through two splitters. One is a 1-to-3 that only has one line running out and could probably just be coupled. Another is a 1-to-2 which runs a line to an upstairs bedroom but which I don't actually need or use. Some of the lines are rather old and bent as well. I'm thinking at least eliminating those splitters would help reliability, but I'd prefer to have a technician do it in case it's decided the lines also should be replaced.

Thanks for any help you can give. I've included what I could gather below. Please let me know if you'd like me to provide anything else.

Log

At any given point in time, the log looks similar to this (connection active/"OK"):

2023-1-24, 09:59:44 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:59:43 Warning (5) Dynamic Range Window violation
2023-1-24, 09:59:25 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:59:23 Warning (5) Dynamic Range Window violation
2023-1-24, 09:57:43 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:57:43 Warning (5) Dynamic Range Window violation
2023-1-24, 09:57:24 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:57:23 Warning (5) Dynamic Range Window violation
2023-1-24, 09:55:43 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:55:43 Warning (5) Dynamic Range Window violation
2023-1-24, 09:55:23 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:55:23 Warning (5) Dynamic Range Window violation
2023-1-24, 09:53:45 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:53:43 Warning (5) Dynamic Range Window violation
2023-1-24, 09:53:23 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:53:23 Warning (5) Dynamic Range Window violation
2023-1-24, 09:51:48 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:51:43 Warning (5) Dynamic Range Window violation
2023-1-24, 09:51:24 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:51:23 Warning (5) Dynamic Range Window violation
2023-1-24, 09:49:47 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:49:44 Warning (5) Dynamic Range Window violation
2023-1-24, 09:49:24 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:49:24 Warning (5) Dynamic Range Window violation
2023-1-24, 09:47:44 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:47:44 Warning (5) Dynamic Range Window violation
2023-1-24, 09:47:25 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:47:24 Warning (5) Dynamic Range Window violation
2023-1-24, 09:45:44 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:45:44 Warning (5) Dynamic Range Window violation
2023-1-24, 09:45:26 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:45:24 Warning (5) Dynamic Range Window violation
2023-1-24, 09:43:45 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-24, 09:43:44 Warning (5) Dynamic Range Window violation
2023-1-24, 09:43:26 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;

When connection drops, I'm seeing this. (Sorry, no pretty formatting ... just copied from a text log):

2023-1-20, 16:30:50 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-20, 16:30:42 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-20, 16:30:31 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-20, 16:30:14 Critical (3) Received Response to Broadcast Maintenance Request, But no Unicast Maintenance opportunities received - T4 time out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-20, 16:29:29 Critical (3) Started Unicast Maintenance Ranging - No Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;
2023-1-20, 16:29:10 Notice (6) Honoring MDD; IP provisioning mode = IPv6
2023-1-20, 16:29:02 Warning (5) B-INIT-RNG Failure - Retries exceeded;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.0;CM-VER=3.0;
2023-1-20, 16:27:23 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.0;CM-VER=3.0;
2023-1-20, 16:27:21 Warning (5) B-INIT-RNG Failure - Retries exceeded;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.0;CM-VER=3.0;
2023-1-20, 16:25:15 Critical (3) No Ranging Response received - T3 time-out;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.0;CM-VER=3.0;
2023-1-20, 16:25:02 Critical (3) Unicast Ranging Received Abort Response - Re-initializing MAC;CM-MAC=[Edited: "Personal Information"];CMTS-MAC=[Edited: "Personal Information"];CM-QOS=1.1;CM-VER=3.0;

Channel information (found this in Basic -> Cable Connection after searching 10 minutes through the Advanced section. Yes, certainly basic stuff, Netgear!)

Downstream Bonded Channels
Channel Lock Status Modulation Channel ID Frequency Power SNR Correctables Uncorrectables
1 Locked QAM256 25 573000000 Hz 3.2 dBmV 39.2 dB 95 135
2 Locked QAM256 21 549000000 Hz 3.3 dBmV 39.2 dB 134 225
3 Locked QAM256 22 555000000 Hz 3.4 dBmV 39.3 dB 161 125
4 Locked QAM256 23 561000000 Hz 3.3 dBmV 38.6 dB 83 123
5 Locked QAM256 24 567000000 Hz 3.2 dBmV 39.3 dB 118 163
6 Locked QAM256 37 645000000 Hz 3.7 dBmV 39.3 dB 142 162
7 Locked QAM256 26 579000000 Hz 3.1 dBmV 39.1 dB 232 140
8 Locked QAM256 27 585000000 Hz 2.8 dBmV 38.7 dB 142 178
9 Locked QAM256 28 591000000 Hz 2.8 dBmV 38.7 dB 142 191
10 Locked QAM256 29 597000000 Hz 3.1 dBmV 38.8 dB 142 144
11 Locked QAM256 30 603000000 Hz 3 dBmV 38.8 dB 159 249
12 Locked QAM256 31 609000000 Hz 3 dBmV 38.8 dB 135 162
13 Locked QAM256 32 615000000 Hz 3.1 dBmV 38.7 dB 140 210
14 Locked QAM256 33 621000000 Hz 3.2 dBmV 39 dB 112 149
15 Locked QAM256 34 627000000 Hz 3.4 dBmV 39.1 dB 133 136
16 Locked QAM256 35 633000000 Hz 3.6 dBmV 39.3 dB 198 251
17 Locked QAM256 36 639000000 Hz 2.8 dBmV 39 dB 0 0
18 Locked QAM256 38 651000000 Hz 2.7 dBmV 38.9 dB 0 0
19 Locked QAM256 39 657000000 Hz 2.8 dBmV 39 dB 0 0
20 Locked QAM256 40 663000000 Hz 2.7 dBmV 39 dB 0 0
21 Locked QAM256 41 669000000 Hz 2.9 dBmV 39 dB 0 0
22 Locked QAM256 42 675000000 Hz 2.8 dBmV 38.6 dB 0 0
23 Locked QAM256 43 681000000 Hz 2.9 dBmV 39 dB 0 0
24 Locked QAM256 44 687000000 Hz 2.7 dBmV 38.7 dB 0 0

Upstream Bonded Channels (Partial Service)
Channel Lock Status US Channel Type Channel ID Symbol Rate Frequency Power
1 Locked ATDMA 13 5120 Ksym/sec 35600000 Hz 45.8 dBmV
2 Not Locked Unknown 9 0 Ksym/sec 10400000 Hz 0.0 dBmV
3 Not Locked Unknown 10 0 Ksym/sec 16400000 Hz 0.0 dBmV
4 Not Locked Unknown 11 0 Ksym/sec 22800000 Hz 0.0 dBmV
5 Not Locked Unknown 12 0 Ksym/sec 29200000 Hz 0.0 dBmV
6 Locked ATDMA 14 2560 Ksym/sec 40400000 Hz 45.8 dBmV
7 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV
8 Not Locked Unknown 0 0 Ksym/sec 0 Hz 0.0 dBmV

Thanks again.

EG

Expert

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97.7K Messages

13 days ago

@EmailMeToTheMoon 

Please redact all of the CM MAC and the CMTS MAC addresses in your error log entries for your privacy. They are considered to be personal information. The posting of personally identifiable information is a violation of their forum guidelines. The forum bot will not allow your post to be seen publically. It flagged your post as "Private".

Visitor

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5 Messages

@EG​ 

Thank you for that. I was wondering why I was seeing "Private". I've removed everything. Please let me know if there's anything else that needs cleaning up.

(edited)

EG

Expert

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97.7K Messages

13 days ago

@EmailMeToTheMoon 

You're good to go. The post is publicly viewable again.

That said. The signal status values at that snapshot in time were OK but the error log entries indicate that something is going on. And there are only 2 upstream channels locked in. Should be 3 to 6. Perhaps there is noise ingress into the line(s) /  an upstream channel / return path impairment somewhere. That can be the cause of the un-bonding of the channels.

There are other signal stat values that can't be read by the modem. They are the "Upstream Rx Power" (Upstream Receive Power Level), the "Upstream SNR Ch." (Upstream Signal To Noise Ratio), and the "Upstream ICFR" (In Channel Frequency Response). These are as equally important in diagnosing connectivity issues as are the modem's stats.


I'm going to escalate your issue to the Comcast corporate employees that are available to these boards. They will be able to poll the CMTS (Cable Modem Termination System) to check for any real-time degradation and / or error reports, see your node / cable plant, and modem health, and see whether or not everything is in the green zone. They can also see a history plot for the modem and poll for those upstream receive signal stats.


You should get a reply here in your topic. Good luck !

Visitor

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5 Messages

@EG​ Thanks again! Really appreciated.

XfinityJohnG

Official Employee

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236 Messages

Thank you very much for reaching out to our team here. I will be happy to look into any service issue from here for you. Could you send me a direct message with the full name and complete address for your service? 

To send a direct message [private message]:

   Click the "Direct Message" icon or  https://forums.xfinity.com/direct-messaging

   Click the "New message" (pencil and paper) icon

   The "To:" line prompts you to "Type the name of a person". Instead, type "Xfinity Support" there.

   - As you are typing a drop-down list appears. Select "Xfinity Support" from that list.

   - An "Xfinity Support" graphic replaces the "To:" line.

   Type your message in the text area near the bottom of the window

   Press Enter to send it

I am an Official Xfinity Employee.
Official Employees are from multiple teams within Xfinity: CARE, Product, Leadership.
We ask that you post publicly so people with similar questions may benefit from the conversation.
Was your question answered? Please, mark a reply as the Accepted Answer.tick

Visitor

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5 Messages

Thanks for offering to look into it. I sent a DM to Xfinity Support per the instructions.

EG

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97.7K Messages

@EmailMeToTheMoon@XfinityJohnG 

Please circle back here and post any possible solutions for the issue here in the open forums so that all readers here may benefit from the exchange / info. This is in keeping with the spirit for which these public help forums were originally intended. Thank you.

I am not a Comcast Employee.
I am a Customer Expert volunteering my time to help other customers here in the Forums.
We ask that you post publicly so people with similar questions may benefit from the conversation.

Was your question answered? Please mark an Accepted Answer!tick
EG

Expert

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97.7K Messages

13 days ago

Quite welcome !

Visitor

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5 Messages

13 days ago

The technician came out and was able to resolve the issue. (Thread started 5 hours ago! Talk about a fast turnaround time.)

Up the pole, there were some wires exposed. When it rained, the process of collecting moisture and drying out was causing interference. I was experiencing intermittent issues, with the connection being fine for days at a time, and then seeing 4-5 disconnects in a day. Being in winter now, weather being more of a factor makes sense, seeing more disconnects in the past few wet months.

Also worth mentioning: apparently an electrical tech had installed a filter on the line in response to the exposed wire. This was why I was down to two bonded upstream channels. Now I've got 6 up, and things are looking stable.

Appreciate everyone who had a role in getting this resolved so quickly! If I should mark an answer as the solution, please let me know.

EG

Expert

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97.7K Messages

13 days ago

Not surprised about the high pass filter. Glad that you got it squared away so quickly !

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